Costly digital technology that has the power to transform education often sits in boxes because teachers do not know how best to use it, a study claims.

Researchers for the National Endowment for Science, Technology and the Arts (Nesta) say there is clear evidence that technology can boost learning.

Their report sets out examples of best practice from all over the world.

Chief executive Geoff Mulgan said: "The emphasis is too often on shiny hardware rather than how it is to be used."

The researchers estimate that schools in England alone spent more than £1.4bn on technology in the past three years but they claim that all too often it is not being used to its "full promise and potential".

The team, from the University of Nottingham and the London-based Institute of Education Knowledge Lab, looked at evidence from hundreds of academic papers, blogs and reviews from all over the globe.